The cases of the Maria Theresa and the America were designed, by Hardwicke, Holderness, and Newcastle, to instil confidence in the Dutch government that the Court of Prize Appeal would safeguard the Dutch neutral rights that had been agreed throughout the first part of the war. They were also designed to instil confidence in British privateers and naval captains and ensure that French colonial trade carried in neutral ships could still largely be stopped and condemned as legal prize. This chapter focuses on the two appellate cases and the legal arguments presented. These are then tied to the legal and strategic maritime thinking of Lord Hardwicke and his creation of the Rule of the War of 1756. This rule became the bedrock for how Britain would understand and negotiate neutral rights over the course of the next major European maritime wars. The basic premise of the rule was that trade that was prohibited to a neutral during times of peace would be considered by the British prize court system to be prohibited in times of war. The chapter, through an analysis of Dutch cases in the Court of Prize Appeal, examines how and why Hardwicke developed this rule.